If windward establishes overlap from astern, leeward can luff her but has to give windward room to keep clear. Since we're on catamarans, keeping clear by tacking involves some boat speed which might mean a bit of footing which obviously conflicts with the idea of keeping clear.

It's pretty clear that the actual solution is "don't be there" but how does this general concept shake out on the course, that cats need more space and speed to tack? Can windward expect room to tack?

First off , yes Windward should be given room to tack.If in the process of tacking ,the Windwards stern comes in contact with Leewards bow,then the Leeward Boat can expect the Penalty.If Windward were to foot off (after overlap is established) and there was contact ,or Leeward would have to manoeuvre to avoid contact ,then Windward would incur penalty.Really the game at the start is to create space to Leeward.Some people lose sight of this fact and there main goal is mess up the Windward boats start.In doing so they mess there own start.Boats on the start line are not your enemy,really unless you are match racing ,is it not necessary to luff a windward boat to the point it needs to tack.The Windwards Boats get out of jail card,is " room and time".That is why it is a good idea to give the Windward boat ample time to luff up.Sometimes it helps to have a loud counter going.Matt B. Should weigh in on this.There was a protest at the Worlds that was similar to this and ,if I read correctly the leeward boat was penalized.

The rules in this scenario are pretty straight forward (well at least as straight forward as the RRS get)...

11 ON THE SAME TACK, OVERLAPPEDWhen boats are on the same tack and overlapped, a windward boatshall keep clear of a leeward boat.

Keep Clear A boat keeps clear of a right-of-way boat(a) if the right-of-way boat can sail her course with no need to takeavoiding action and,(b) when the boats are overlapped, if the right-of-way boat canalso change course in both directions without immediatelymaking contact

If she establishes an overlap from clear astern, then the onus is entirely on the windward boat to keep clear of leeward. No ands, ifs, or buts, the windward boat is going into no-man's land if she puts herself in that position and she must keep clear.

Room The space a boat needs in the existing conditions, including space tocomply with her obligations under the rules of Part 2 and rule 31, whilemanoeuvring promptly in a seamanlike way.

If the leeward boat changes course (luffs), she has to give the windward boat room to keep clear. She can not slam her boat head to wind, but she can turn to windward quickly and the windward boat is still required to keep clear. If the leeward boat can not turn to windward to luff without immediately contacting the windward boat, then the windward boat has fouled leeward.

The leeward boat may force the windward boat to head to wind, but she may not force the windward boat beyond head to wind (force her to tack), although the windward boat may choose to tack in order to escape from the leeward boat.

If the windward boat tacks, then rule 13 kicks in:

13 WHILE TACKINGAfter a boat passes head to wind, she shall keep clear of other boatsuntil she is on a close-hauled course. During that time rules 10, 11 and 12 do not apply. If two boats are subject to this rule at the same time, the one on the other’s port side or the one astern shall keepclear.

In essence, a boat which is tacking is required to keep clear of one which is not, so the previously windward boat would still be required to keep clear.

In this situation (windward boat establishing an overlap from astern), the rules are no different at the starting line.

The only variation of the windward/leeward rule that applies at the starting line is when a leeward boat establishes the overlap from clear astern of a windward boat. If a leeward boat establishes an overlap from clear astern, before the start, she may luff the windward boat head to wind. However, after the starting gun Rule 17 (Proper Course) kicks in and the leeward boat must sail her proper course, which would be a close hauled heading (i.e. she can not luff after the gun). Again, this rule only applies to the situation where the leeward boat establishes the overlap from astern of the windward boat. The original post was talking about a situation where the windward boat established the overlap from clear astern, so no changes to the rules as described in my prior post.

More generally, if W can't keep clear within the space that she gave herself, then she is S.O.L. It doesn't matter if her plan for keeping clear is to tack, to luff head to wind, or to try to stall and then dip below L. If W establishes an overlap on L from clear astern, then W is obligated to keep clear of L. L is limited in how she can change course in response to W, but if W does not keep clear of L, then W has fouled L.

The incident that happened at the 16 Worlds involved a leeward boat trying to defend itself from being rolled right after the start. They luffed the windward boat which did not keep clear - obviously since the skipper of the leeward boat had her life jacket snagged by the windward boat's rigging, nearly pulling her off the boat. As a result, the leeward boat went head to wind and subsequently drifted back into the pin boat (where I was) before regaining control. The windward boat sailed on.